Add support for proto in testutil.CompletedRequest, for testing proto… (#103)

* Add support for proto in testutil.CompletedRequest, for testing proto-related message request/resp.

* Use a handler registry to allow user register custom response handlers.

* Cleanup Go modules.

* Use generic io.Reader, to allow more flexibiltiy.
pass in complete content-type so that user can have more flexibility.

Author: yangzh-deepmap

request_helpers.go

@@ -167,13 +167,13 @@ func (c *CompletedRequest) UnmarshalBodyToObject(obj interface{}) error {
 
 	// Content type can have an annotation after ;
 	contentParts := strings.Split(ctype, ";")
-
-	switch strings.TrimSpace(contentParts[0]) {
-	case "application/json":
-		return json.Unmarshal(c.Recorder.Body.Bytes(), obj)
-	default:
-		return fmt.Errorf("no Content-Type on response")
+	content := strings.TrimSpace(contentParts[0])
+	handler := getHandler(content)
+	if handler == nil {
+		return fmt.Errorf("unhandled content: %s", content)
 	}
+
+	return handler(ctype, c.Recorder.Body, obj)
 }
 
 // This function assumes that the response contains JSON and unmarshals it

response_handlers.go

@@ -0,0 +1,40 @@
+package testutil
+
+import (
+	"encoding/json"
+	"io"
+	"sync"
+)
+
+func init() {
+	knownHandlers = make(map[string]ResponseHandler)
+
+	RegisterResponseHandler("application/json", jsonHandler)
+}
+
+var (
+	knownHandlersMu sync.Mutex
+	knownHandlers   map[string]ResponseHandler
+)
+
+type ResponseHandler func(contentType string, raw io.Reader, obj interface{}) error
+
+func RegisterResponseHandler(mime string, handler ResponseHandler) {
+	knownHandlersMu.Lock()
+	defer knownHandlersMu.Unlock()
+
+	knownHandlers[mime] = handler
+}
+
+func getHandler(mime string) ResponseHandler {
+	knownHandlersMu.Lock()
+	defer knownHandlersMu.Unlock()
+
+	return knownHandlers[mime]
+}
+
+// This function assumes that the response contains JSON and unmarshals it
+// into the specified object.
+func jsonHandler(_ string, r io.Reader, obj interface{}) error {
+	return json.NewDecoder(r).Decode(obj)
+}